The present disclosure relates to a magnetic memory device which is laminated by a plurality of vertical magnetization layers including a memory layer and a reference layer through a nonmagnetic substance, and memorizes information by reverse magnetization in a spin torque generated when a current flows between these layers, and a method of manufacturing the magnetic memory device.
In information devices such as computers, high density DRAM (Dynamic Random Access Memory) operating at high speed is widely used as a RAM (Random Access Memory). However, since DRAM is a volatile memory in which the information disappears when power is turned off, a nonvolatile memory from which the information does not disappear is necessary.
As a nonvolatile memory candidate, MRAM (Magnetic Random Access Memory) memorizing information by magnetizing magnetic material has attracted attention and is undergoing development.
As a method of memorizing MRAM memorization, there is a method of reversing the magnetization by a current magnetic field, for example, as disclosed in Japanese Unexamined Patent Application Publication No. 2004-193595, involving inducing a magnetization reversal by injecting spin polarized electrons into a memory layer directly. In particular, spin injection magnetization reversal, which can reduce current for memorization and reduce the size of the device, has received attention.
Furthermore, in order to refine the device, as disclosed in Japanese Unexamined Patent Application Publication No. 2009-81215, for example, a method for utilizing a vertically magnetized layer which enables the magnetization direction of a magnetic material to become vertical is being studied.